The Fourth Buddhist Council was held during the reign of:

Correct answer: (d) Kanishka

Explanation

The Fourth Buddhist Council was held in Kashmir (at Kundalavana) under the Kushana king Kanishka, in the 1st–2nd century CE. Vasumitra presided and Ashvaghosha was his deputy. It is linked with the rise of Mahayana Buddhism.

The councils:

• First: Rajagriha, under Ajatashatru, soon after the Buddha's death;
• Second: Vaishali, under Kalashoka;
• Third: Pataliputra, under Ashoka, presided over by Moggaliputta Tissa;
• Fourth: Kashmir, under Kanishka.

Menander (Milinda) is known from the *Milindapanha*, and Harshavardhana held assemblies at Kannauj and Prayag, but neither held a Buddhist council.